Description: (Applicant's Description) The mission of the Core Flow Cytometry Facility is to provide Cancer Center members with ready access to routine and complex flow cytometric procedures, along with consultative services required for members to make full use of the power of this technology. Facility instrumentation includes a Becton Dickinson (BD) FACS Vantage, a BD FACS Calibur, a BD FACScan and a Compucyte Laser Scanning Cytometer, along with associated computers, all linked by a local area network. This Core has served 5 Cancer Center Programs during the grant period and interactions among all programs are noted in the authorship of 55 publications dependent on the services of the Flow Cytometry Core. Monthly Flow Cytometry User Meetings are held, which foster continued interactions and education. Core usage has increased 113% over that reported in the last application, and a continued significant increase is anticipated given the relatively recent arrival of new investigators (Drs. Malcolm Mitchell and June Kan-Mitchell) and the recent bringing online of the FACS Calibur and the Laser Scanning Cytometer.